Elevating and depressing mechanism for mowers



w. F. MILLER ET AL ELEVATING AND DEPRESSING MECHANISM FOR MOWERS mm 74 Mwm Sept. 28, 1954 Original Filed May 18, 1951 ATTURNflYj- Se t. 28, 1954 w. F. MILLER ET AL ELEVATING AND DEPRESSING MECHANISM FOR MOWERS 3 Sheets-Sheet 2 Original Filed May 18 1951 p 1954 w. F. MILLER ETAL ELEVATING AND DEPRESSING MECHANISM FOR MOWERS 5 Sheets-Sheet 5 Original Filed May 18, 1951 INVENTORY WILLIAM F. MILLER OMAR L. CUNNINGHAM MARK W. MAKI Patented Sept. 28, 1954 ELEVATING" AND DEPRES'SING MECHANISM FOR MOWERS William F. Miller, Or'n'ar L. Cunningham, and Mark W. Maki; Minneapolis, Minn., assignors to Tom Manufacturing Corpoiation of Minnesota, Minneapolis; Minn., a corporation of Min nesota;

Original application Mayqis, 1951, Serial No. 227,064. Divided and this application May 21,. 1951-, Serial No. 227,442

Thisiinvention relates: to. rotarymowers. More ,particularly it relates to rotary mowers constructedv for wide-swathe-d mowinggenerally at relatively high speeds and"v wherein- L80turns are :made att'he-end of the area; being mown".

Gurrent. requirements in mowing large" areas such. as air ports, golf courses, and the like specify that a rotary mower, utilized for such :areas, should becap'ableof executing a 180? turn without skipping or leaving any unmown area between the adjacent. swathes in the vicinity where the turning operation takes place. Such a rotary mower should; for efficient operation, be capable of cutting a wide swathe and of being operated at high speeds. It isimperative that there be no skidding of the weight-bearing wheels during such a turning: operation to prevent the sod or turf frombeing torn anddamaged. It is equally important that some means be provided to prevent serious bouncing of the mower while passing over relatively rough terrain at high speed. It is also. imperative that some means be provided for either quickly substituting other blades for cutting: blades which have become dulled or; for'prev'enting such blades from -becom ing dull to thereby minimize the loss of time required for changingblad'es; our invention is directed toward'ia satisfactory" solution of' 'tlie'se problems; The" inventions disclosed and not claimed' hereih are also' disclosed in our divisional application SerialfNo. 227;'64', filed Ma-y- 185-1951, and entitled':Multirotor Mower and are claiined therein.

Itis a general object-ot'our invention to providea novel and' 'improved' rotary mower of rel atively'simple construction and of increasedeflicien'cy when in operation;

A more speeifie objeet-is to provideanovel and improved mower utilizing a plurality of rotary cutter units -m0unted on spacewvertical axes and capable of completing a- 180 tu rnwithout slz ipping any of: the grass? and/or weeds between swathes and without: lateral skidding oi the wheels with consequentfi'in'juryto the mew-n sur--' face au'idzwith excessive wear upon' th'e 'tiresa Another object is =t0 provide a rotary: mower having a plurahtyofFrotaryrcutteruni-ts mounted in; a. sweep arrangement 1 to" cut a: continuous swathesthea endsz of" which. meet; the: axis the wheel structure uponwh'icli thee-mower turns-and the;main-portiomofwhich eXten'ds or "lies? to one side: ofi'such: axis;

Anotherxobjecti is to provid' a novel a'nd inrproved meehanismifor' maiI-Itaini g the respective sections-mica multirotorrmower iir contact witrt 2 fihe grou'nd'at 2311 times despiteth'epassage thereof over rough terrain;

Another object is to provide a rotary inovir constructed to fioat with the ccntour or the" face to' be mowed and' to permit section's thereof to pivot vertically" With respect to cl' l ether while passing overuneven terrain.

Another object is to provide a" never and iniproved ro'taryniower portions of are swingafblevertically'to anout ofi-wa-y position and hav ing'noveland: improved elevating mechanism for accomplishing such movement.

Another object is to provide a rotary mower having a plurality of rotary cutterunit assemblies capable of ready vertical atljlistinent" with respect to the" surface to be mowed;

These and other objects and" advantages or our invention will be more apparent from the renewing description made connection with the accompanying." drawings} wherein like reference characters: refertb similar-parts throughout the several views" and which: i

Fig; 1- is aatop" plan View of one-embodiment of ouriinventionwitha portion of the cowlbiolien away' from? one" or the lateraicutter" unit assetsblie's.

Fig; 2 is atfront elevatiorial' view or the same with the cowl and protective guard retrieved to more clearly show the respective cutter Fig. 3': is a'side elevational view of oneerhbodimen-t ofr our irivent'ioiiwiththe lateral entendihg assemblies broken aw'ay to "more clearly show the relation: between: the remaining parts; i

Fig; 4" is an? enlargedfront ele'vation'alsview taken approximately aiong mewsdr Fig. 1'.

Fig 51' is" a". diagrammatic- View showii'ig" the exact path followed: by the supporting structure for an'e'mbodimentf of our invention in executing a 1-30" turn= without skipping" or" skidding! Fig. 6 israri enlarged vertical" sectional taken-s approximately along line": ii -6* of Fig 1 Fig: '1' is an enlarged elevatienal' view taken approximately alongfl'ine -ll' of l i'g; l -wit he necessary partshrohemawatr to marine-Sucre a View- Figs-s isan enlarged sectional view tahen alofig line: 8--& of Ei'g-i 7-. 4

Fig-L 9 1s: an' ei-ilarge"d elevation-ail approximately a view taken 1- may be supported by a tractor or other propelling device and the rearward end of which may be supported by Wheels 130. and 13b mounted on an axle M which extends transversely to the frame F and to the direction of its movement. If desired, of course, the frame F may be provided with a propelling mechanism of its own and in that event a set of wheels adjacent the forward end thereof would normally be required.

As shown, a motor i 5 is mounted upon the ambulant frame F to provide a source of rotary power. A primary drive shaft I6 is connected to the motor [5 by universal joint I? and to transmission gear (not shown) in a transmission housing l8 by a second universal joint l9. These transmission gears (not shown) in a transmission and arranged to step up the speed of the rotary motion created by the motor I5 and to make possible a reversal in the direction thereof. A sec ondary drive shaft 20 is likewise connected to these transmission gears by a universal joint 2! and to bevel gear 22a by a fourth universal joint 23. As best shown in Fig. 4 this bevel gear 22a is housed in a gear box 24 which is disposed directly beneath the frame F. This bevel gear 22a cooperates with another bevel gear 22b which is mounted on a horizontal and. transversely extending splined shaft 25.

The splined shaft 25 extends laterally in both directions through the sides of the gear box 24 which has bearings 26 for that purpose. This shaft is made in sections, each section. being splined to another section by splines 25a to increase the length of the shaft. The splined shaft 25 extends through the bearings 26 and carries bevel gears 2'! at regular intervals along its length. Each of these bevel gears 2'! is disposed within a gear box 2811. The lower portion of each gear box 28a is constructed to provide a journal 29 for a vertically extending and depending shaft 30 which carries a horizontally arranged bevel gear 3! in position to cooperate with the bevel gear 21. Each gear box 28a is open at both its sides and is adapted thereat to be removably connected to relatively long housing segments 3211. These housing segments 32a carry the splined shaft 25 and serve to support the next gear box 28a which may be connected to the outer end thereof.

As best shown in Fig. 2 a gear box 33 is rigidly connected to the outer end of each of the longer housing segments 32a. This gear box 33 is formed quite similarly to the gear boxes 230: but is provided with an outwardly extending bracket 34 on its outer side. As best shown in Fig. 1 this bracket 36 is provided with a pair of pivot rods 35 at the ends of each of its arms.

Pivotally mounted on the pivot rods 35 is an angled pivot bracket 36. As best seen in Fig. 1 the angle of this pivot bracket 36 is such as to cause other gear boxes 2% and housings 322) which may be connected thereto and which are constructed similarly to the gear boxes 28a and housings 32a to extend rearwardly with respect to the frame F. The bracket 34 and the pivot rods 35 are arranged so that the angled pivot bracket 36 is mounted for swinging movement on a horizontal axis extending longitudinally of the frame F and in the general direction of movement of that frame. The splined shaft 25 is connected in driving relation to a similarly splined shaft 31 by a universal joint 38. It can be readily seen that a gear box 2% may be rigidly connected to the outer end of the angled bracket 36 and that a housing 3212 may be connected to the outer side of such gear box and that additional boxes 28b and hour ings 32b may be connected in alternating sequence until the length of such an assembly is as great as may be desired. Each of these gear boxes 221) has a vertical shaft 33b mounted for rotation and each is adapted to be connected to such a housing 322). By referring to Fig. 1 it can readily be seen that this results in a sweep back arrangement with respect to the frame F.

The final or outermost housing 321) on each side of the machine has a right triangled plate 39 secured to its outer side by Welding or some other suitable means, A link as best shown in Fig. 9 is pivotally connected to the forwardmost corher of this plate 35 and extends rearwardly therefrom. A ratchet arm ll with handle 42 extends upwardly from the rear end of the link dc to which it is pivotally connected and passes through a guide member 53 which has a slot therein for that purpose. This guide member 43 is welded to the upper corner of the plate 39 and has a transversely extending pin 54 extending therethrough to cooperate with the teeth 45 of the ratchet arm 5!. The set screw ii? extents inwardly through the guide member 43 and into its slot to abut against the rear of the ratchet arm 4 I. An axle 4'! is mounted on the outer side of the rear end of the link l5 and carries a supporting wheel 48 on the outer end thereof.

Mounted on the ambulant frame F and tie pending therefrom are four mounting plates 49 each of which is mounted on the opposite of the frame in longitudinally spaced relation. Pivotally connected to the lower portions of each of the forwardmost two of these plates is a spring 583. The rear end of each of the sp-..ng-s 5B is connected to its respective rear plate by a link 5! for swinging movement therebetween. The medial portion of the axle it is constructed in the shape of an I beam, as best shown at 52 in Fig, 3. This I beam is rigidly conn cted to the spring 5c by clamps or other suitable means. Thus the entire frame F is supported by the wheels [3, its axle i i, the spill and their mounting plates 4d. Formed on upper surface of the I beam adjacent each side of the frame F is an upstanding bracket 53 which is pivotally connected by a link 54 to the rear end of a lever arm 55 as best shown in 'Z. The forward end of each lever arm 55 is pivotally mounted on the frame F as at 5%.

Pivotally mounted within the interior each lever arm 55 by means of a pair of ears 52 a pivot block 53. The cars 5'3 are arranges s that the pivot block will pivot on a sul stantialh horizontal and transverse axis with respect to the frame F. A suspension arm 55) is pivotally connected at its lower end as at to tie housing directly below and extends upwardly through the pivot block 53 a substantial distance. Spacing holes 6| are formed in the upper portion thereof. A rubber bumper or cushion 52 and a collar 63 are slid over the upper end of each suspension arm 59 as shown in Fig. '2 and a lock pin 64 is provided to lock each collar to its pension arm in the spacing hole selected for that purpose. Formed integrally with some of the housings 32b is an upfaoing bracket As best shown in Fig, 6 triangularly shaped support arms 66 may be secured to these brackets. Secured to the support arms in superimposed relation is a cowl 6! which extends throughout the length of the cutter assemblies. Depending from the for-- ward and rearward edge of the cowl 5 are a plurality of closely spaced lengths of chain 98 anaconda which extend tozza pointsaashortrdistmceiabaw the; surface. tab-e mowedz.

Removably: secured: ton then-lowers ends; nortion oireach ofcthe; shaftsflfliazndifllnas; best shown ingEigefi israuhorizontalzdtscc659i Theseediscs 6c; are; connected! by; verticall-sr extending pivots lflizto; aespaced collar disc: H 1 Mounted: on: of the: pivots we in free-z: swinging: relation 1; ism: a generallm triangularlyo shaped cutterr elementr. o1! knifev 1-2: Thesechnives; 1212 areesharpened; alone; both-:ozf thesidexedges;andtareepivctedzatttheebase ofzjthe; triangle solthati whernthe :disce Swami: the collar; Hr. rotate: rapidly; the: blades: will: extend radially; therefromand-ztheiorwardandith z trait-e nc edseithereofxwilhbesshame,

Asabest shown in Eigs.- 2t'andm3ealbracinastruc; ture havingz-athe:generalishapeeofiatparailelogram is;provided:fort-maintaining thencntten elements inasubstantiallmhorizontalpositiona Thisabrace ing: structure includes-.aalong--;eachtsider ot the frame Ea pairi'ofiaverticallysspacedzperaliel brace ingtzarms; .thezzupperrcnenla of; whichisespivotailw' secured;td;:the=.:frame Ei'with gyplateflk, upperzbracing arm extendsrdiagonalire downward: in; nd utwar ly: andii is pivotalhc connecteds. at: the tower: end tman :ear 15,101: atheston of: theasgcar born 28*; i po e immediatelyt on the braeketish Thisilissbfisii showm'. Tiara The lowers-l 76v or '7 these parallel a armsi extends l dQW' t ward-1y; and inwardlyrand isivpivotallyrconnected or h nfr me alt its;-- upperzend 1 by at; mat 1; 1 which,dep ndstrom-the framefilr Therlowerzend onthepbracinga arm; 16. is: pivotallmconnected-to the; lowerssideyofthea gear :bQX'flil-fiby; avhorizontalhz and forwardly extending: pivot bracket 1.1a:

Wherever herein the; term 1; rota-rye cutter Y unit is susedit is intended o=; reiem'toaangeamboaa: 2-3,; 2:8.h-or 3i3:in ;conjl1n0.t.ii0n:withitsverticalzzshafit 3.1Jrr 30 he i c '69::12hfif300llfl1fdi a cutter elements J21. Vilherevex;v t cutter unit assembly is used herein to. connote' a plurality: ofgsuch, rotamfcwttenfunits conn cd ethcr into amassem-blw morabieeas ea in -l mma Thusithe.nluralityvotiirotar cut-tor. units; extending:- laterally fronteach: 015-; the br ckets :34: m onsidered:totconstttute:atlateral extending; rotary; cutter unit}, assembly and:. the, plurality of rotary; cutteri unita. connected. toe gather: betweem the? brackfits 314; arleeconsidered to constitutew a centrally and. transverselmtdais: posed cutter; un-it: assemblyr:

} Iihe 1- cutter, elements.- of, the respectivez. rotarg cutteri-units; are; synchronizedpwith, those-=;-ot{the adjacent cutter. unitrandi \the unitsaarer arranged clo ely, enough together:=so,.. thatlthe, cutter .elee ments, overlap The.outermos t,.. or, the; cutter units i of each lateral. assembly, is disposedlsoethat itscutter. elements, at. least intersects. the, axis 0t. its respective supporting. wheelv structure aria i'acent, thev outermost. wheelji. 4187., This. is best shown in Fig. 1. i

o fa i e hena ee oiourrqt rmmower throu h? at s a di oth r relatively narrow-a pas; aees' to i sure that ithfi: r spec ive cutter. 215-. semblies will he preventedfrom bouncing ,;while passing; over. roughv terrain; athrelativelv high speeds, .we; have provided a, combined elevating and: depressing mechanism to bej used in .con.- junctionwiththese assemblies, ThiSimechani'sm hasb'een, indicatedigenerall'y as Miami may in; cludetaslshownapairnoiflongitudinallynspaced,inrvertede. v-shaped supports. 18;, with horizontal; armsJBa/mountedontoplofitheirameandextend, ing laterally-therefrom.- A rpivotpmembenrlayis providedrand secured-anther ancxzoftthe and upon 7 thisspivotl member: pivotallw mounted a pal of: oppositely extending: hydraulica-cylinders 8.0.11 Theses cylinders:together'may'be considered tosconstitute anhydraulic. cylinder? assembly and each of them: is provided: with at piston (not shown)vv which hasa pistonrod'ratl extending out wardlya therefrom. Aszbest shownt'iniFig; 2 these cyiindersrflilrare :arrangedsotthattheJpiSton rods armwillzextendiaterally with respect" to the frame Eachwof' the rods 8 I: is; provided with :a: U- shaped: bracket. 82: at: its outer: end and this bracICetLis pivotally. connected to a horizontally extending: pivot; shaft: or pin 831 which extends through pairrofzrspaced' pivot arms 84; These pivot;:arrns:. 84:: am pivotally mounted at their lower ends: on their respective horizontal" support arms 18a. The cylinders: are supplied bysthe motor! 5 with :a source ofrhydraulic power.

Bivotallymountedon teach horizontal pivot pirr or-zshaft 183: isaa lever: arm. 852 As best shown in Fig. 2.:this lever varnr isamounted by one *otits end portionszandshasisadisc or drum-like structure- 8'6 formedi. integrally therewith or. fixedly secured thereto, This-disc 8331's providedi with a groove 81 inzits; outerr'circumferential surface; The outer endrxpi'eahh lever arm; 85 1s: pivotally connected withsallitt armBBriwhich in turn is pivotallycone nected= A to: an, upstanding 1 bracket 89? fixed-ly se cured tto ttheetopiizof' ahousingtlb as at 9i] at=a pointuspacedxbetweenstheends: of the lateral cutter.'unit;assemblyz- A cableui) l" is anchored on: the outer end portiontotzeachofithe armsa'lfluiat a point'outside of thee pivot points oi the: lower: end a of" the pivot arms 84; Thisscableeml extends: upwardly around the disc :861: and: within the groove: 81- and is-rsecured inznany ssuitable"manner (not-shown) to-the discs itself at a points partway therearou-nd, The cable t-textends: inlthe directionin which the lever arm 8=5irwiil swingr when the lateraliassembly moveslzdovvnwardly;

A pair of cables 92 extend outwardly from-leach of. thesenda of a relatively strong contractile typezspring: 93 which is disposed b'etween' the :discs 8'51;v Each of: these cables 92 extend: around a disc: 8561mm the: opposite direction-irom the cable 951 andiis fixed1y secured tothe disc at a point partway. therearoun'das a best shown in Fig. 4i The :length ofi; the; cables 92' are such that when theslateral assemblies; are loweredthe: spring 93 will: necessarily be extended substantially. The length-of fthecables-9 i is such that when pivot arms-84* move to verti'cal position the respective discs ii'iifiwill be caused to rotate-abbut-the pivot shaft 88to:causa-the outer end of the lever arm flfi toswina upwardlyand draw its lift arm Bit-andthe lateral: assembly connected-thereto upwardly. These cables 9 l are alsoof-sucha length that WhBII-f the v-structure; is in the position shown in E i-g z the cables are relaxed.

In operation the-embodiment of" our invention shown in Figs: 1 -10 may be drawnbehi-nd'a tractor or other: propelled vehicle to accomplish the mowing function Fig 5 shows diagrammatically the manner in 'wh'ich a--180"-"'turn=wi11-be=executed withthismowerwith'out-skipping of unmown areas andfiwithout skidding-- 0fthe wheelS sup porting thee mowing structuren The let-t1 hand portion of #Figa: 5'1 shows the multii-rotor mower: beingn drawmirrzth'ei direction indicated? (toward the top-of thee-drawing): andindicatesitheepaths followedbyvtheirespectixrerwheeis:duringntheetum= ingr onerationz; Theerightshandr':wheelliwhichsis:

mounted adjacent the outer end of the right hand laterally extending cutter unit assembly backs up during the turning operation so that when the turn has been completed it is in the position shown in broken lines. The rest of the mower is also shown in broken lines after the turn has been completed. It can be readily seen through reference to the line YY that the completion of the 180 turn results in a substantial overlap by this right hand wheel. Thus there will be absolutely no skipping of unmown areas possible in the vicinity of this right hand wheel. This obviates any requirement for additional turns or additional mowing trips across the ends of the area to be mown to insure that all of the grass and weeds which ordinarily is missed during such turns has been mown.

When a 180 turn is executed as shown in Fig. 5, each of the respective wheels completes the turn without any skidding relative to the surface being mown. This is accomplished as a direct result of each of the supporting wheels being mounted along an axis lying in the same vertical plane as the axis of the wheels supporting the frame F. Close examination of Fig. will reveal that the turning point in such a turning operation is disposed immediately inside the outermost wheel on the side toward which the turn is being made. Since each of the wheels is continually maintained at all times throughout the turning operation along an axis which is in the same vertical plane as the axis of the frame supporting wheels, it is not necessary for any of the other side supporting wheels to skid or slip sideways in order to complete the turn. Thus there is no skidding or slipping of the wheels or their tires over the surface being mown. Since there is no slipping or skidding, there will be no consequent damage to the surface being mown and there will be no excessive wear on the tires mounted on the wheels executing the turn.

One important feature of our invention is the sweep back arrangement of the rotary cutter units, each of these cutter units being arranged so that the various cutter elements are syn-chronized and overlap with respect to each other. By arranging the rotary cutter units in a continuous line with such overlapping relation existing therebetween, it is possible to have additional supporting wheels such as the wheels 48 without the objectionable skidding and excessive wear normally encountered since such a sweep back arrangement permits each of such supporting wheels to be mounted along the same axis or at least along an axis in the same vertical plane as the axis for the frame supporting wheels. This sweep back arrangement, of course, could be varied to provide a sweep forward arrangement by placing the central rotary cutter unit assembly rearwardly of the frame supporting wheels Ilia and l3b and by causing the laterally extending assemblies to extend forwardly to a point where their supporting wheels are disposed along the same axis as the wheels supporting the frame F. Thus we have provided a mower wherein a continuous wide swathe may be accomplished and wherein the mechanism for accomplishing such a wide swathe does not have the objectionable features previously found in mowers attempting to cover such wide strips.

The lever arm 55 in conjunction with the suspension arm 59 and their associated parts cooperate to provide a dampening effect with respect to the vertical movement imposed on the central cutter unit assembly as a result of the frame supporting wheels I3a and 13b passing over rough terrain. For example if one of the wheels 13a and 13b strikes a bump, the I beam 52 will move upwardly and carry the rearward end of the lever arm 55 upwardly therewith. By referring to Fig. '7 it will be readily seen that the central cutter unit assembly will be caused to move upwardly as a direct result. The upward movement, however, is substantially reduced because the suspension arm 59 is attached at approximately the longitudinal mid-section of the lever arm 55. Thus if the rearward end of the lever arm moves upwardly one foot, the suspension arm 59 which is attached to the central rotary cutter unit assembly will be moved upwardly only approximately one half that distance.

Another result of the use of the lever arm 55 and the suspension arm 59 in conjunction with the spring 55 is that the cutter elements are urged downwardly at all times with respect to the frame while the machine is passing over a bump. When one of the wheels passes over a bump, its associated leaf spring 50 is compressed until its resistance is sufficient to bear and lift the weight of the frame. As soon as the wheel passes over the crest of the bump, the leaf spring urges the wheel downwardly. Hence, even though the frame may continue to follow the trajectory given it by the impact of the wheel upon the bump, the cutter elements will be lowered with respect to the frame to off-set such movement and minimize its undesirable consequences. In other words, the frame is indexed to the spring in such a way that when the frame rises, the cutter element is maintained at a low level because the wheel is maintained in contact with the surface of the bump at all times and hence the rearward end of the lever arm 55 is lowered in conformance with the surface over which the wheel passes.

It is possible to adjust the elevation at which the respective cutter elements are disposed above the surface to be mown. This is accomplished by removing the lock pin 64 and adjusting the cushion 62 and collar 63 so that the lock pin will extend through the spacing hole 8i located to provide the desired elevation. In this manner the elevation of the central assembly and the elevation of the inner end portions of the lateral assemblies may be adjusted. The outer end portions of the lateral assemblies may be adjusted through the adjustment of the ratchet arm ii. To accomplish this adjustment the set screw 55 is loosened and the ratchet arm M is drawn rearwardly by the means of the handle 52 and raised or lowered to the desired elevation whereupon the ratchet arm is again moved forwardly so that the teeth 45 may engage the pin 44. The set screw it is then again tightened to secure the ratchet arm in place.

Bracing structure is required to insure that the shafts 36 within the rotary cutter units are at all times maintained in substantial vertical position despite the vertical movements of the central assembly. By referring to Figs. 3 and '7 it can be readily seen that means must be provided to insure that these shafts 35 will not tilt off their vertical positions. We have provided what we choose to call a parallelogram type of bracing structure. By referring to Fig. 3 it can be readily seen that the central assembly of rotary cutter units is free to move upwardly and downwardly and that it will at all times be prevented from tilting its shafts 36 off vertical position by 'ournovel "bracing structure. In other words, since the 'br-a'cing amrs 1-3 and :16 ware parallel and are pivotally -connected to the eentral assembly, these arms will move with' theas sembly :Lto. :c'maintain the same rin its 'proper orientation and will: at all :times remainxparallel toeach other.

When :the device is ini the position 'showni-in Fig. 2 the laterally extending positions or the pivot-= arms-84 causethe cables 92 tofltension the spring "53. Sinee the P springpu-lls inwardly on the 'cable fl, each of the 'discs elifiand the lever arms 85 are'urged -to rotate so that th'emuter end 'portions "of the lever arms will be urged downwardly to'exert a depress'ing' efiect on 'each of the lateral assemblies. In other words, a downwardly directed pressure will be "exerted through the lift arms fifl uporr each of= the lateral assemblies and that urge will remain constant without any pressure whatsoever being exerted by the pistonro'ds 8 I I or the hydraulic assembly. This downward pressure *serves the -'-very i useful function or maintainin'g the euter support wheels'in contact with the ground at all times and thus prevents bouncing of the cutter unit assemblies-and irregular, iunsatisfaetory=mowirig operations. There "is a *great -teniiency for bouncing of these cutter unitswhilepassing over rough terrainat highspeeds and"this-depressing mechanismeffectively preventssueh *units from such bouncing movement. As a result, the mowed surface has an even and 'highl-y sat-isfactory :cutdespitexh'e' fact 'that the mow ing operation is performed at high speeds.

Because a mower of i suchwide proportions is utilized, there is need i to be -=-able to art-1 collapse or withdraw the 'laterall-y extending pertion's of the device. This is important sin'ee it is oftennecessar-y to move such a devi'eethrough relatively narrow gates or other narrow passage- Wa'ys. -Itis'a1so important to beable to elevate the-cutter units asu'bstantialdistance above 'th'e ground to permit more rapid transportation df the device when not--enga ged in puttingor 'mowing operations. It is obvious, of do'urse,ithat' i't is possible "for-each of the lateral a'sseniblie to pivot vertically about the axis of "the pivot pins 35 *which-conne'ctthe brackets 3 1 and 36. We have "provided a combined -elevating a'nd "depressing mechanism "for the purpose "of controlling such pivotal movement.

-"W hen it is ---desire'd*to elevate lateral a -ssemblies, the cylinder assembly may be activated by the motor a l 5 to "draw the pistons and theirbrackets 82 inwardly. By referring to Fi-g. 2*"it can be=seen that the'result-of thisinW-ari-l movement is tomove=the pivot=-shaft t?3 both inwar'dly and upwardly. The -inwar'd movement, however, exceeds the upward movement 'so-that the tension on the spring 93 'w'i11 be relaxe'd.-

Since the upward movement of the Y pivot' sha'ft 83*an'd its inwardmovement both tend 'to rnove that shaf t farther awayfrom the anch'or 'of the cable '9 I, this'movement"results'in these discs s fi being caused to rotate. The direction "of rotation 'is -'suchas to cause the outer "end --portions of the lever 'arms 85 130 swing-npwarizl'ly, pivoting or-- swinging around "the pivot' sha'f-ts at sothat 'when'the 'pivot arms 84" have reached approximately vertical position, the lateral 'as se'mbl-ies will havebeen elevateda "verysubstantial distance. Once the 'lateralassemblies "have been elevated, they -may be "maintained this position by locking th-e hydraulic *assembly in any-well knownnonventionaldnannr.

When it is des'ireHto a-gain-lower 'these lateral assemblies, -the 'hydraulic assembly is actuated by them'otcrF5 toucadse thepiSton 'rods- Bl to move outwardly. This outward movement will gradually permit the "lowering of the assembly to 'the' positiomshoum in Fig' Q but bfcre reaehing that position 'the-'=tension on the -eables 9! will have been relaxd arid the =tensionon the cables '92 will have ag-a m 1 been imposed thereupon toprowide thedewnward 'tnrust upon 'each of the lift arms &8. This constant-'-"downward thrust eiiectively prevents t'he lateral as'sezrifibli es from performing 1 an uneven i'mowing "operation as a resd-lt'o'f bouncing caused by the -passagewdf the device over rough' terrain at 'rl-ativelyhi'gh speeds.

We *haVe provided a m'ulti-rotor mower capable of cuttingan'extre'mely'wideswathe'and of being operated-over relatively rough *terrain at speeds approximatelyaslnghas "-25"mi-les'= "p hour. *It can be readily seen that our 'mo-werwill perfect'a r turn= without-any damagewhat'soever to thesurfa'cebeingmown; with-out any excessive wearupon" thetire's,andwithout leaving any unmown "portions in the area "of the'point about which the "turn "is "made. Our "mower is constructed to'eliminatethemarked elevational irregularities in "the cutting "operation "Whih normally results from mowing at high speeds over rough "terrain. *This "of "course is -accompiished 'by' our dampening mechanism in "combination with'our depressing mechanism.

'It should be noted "that we have "provided 1 a mower "which eliminates *a substantial loss or time by "obviating any requirement for "changing the "knives as soon "as the conventional "single cutting edge "is dulled. We have provided -cutting elements with two Cutting edges and have provided means for reversing the direction of rotation of "the cutter elements sothat the secon'd "group of cutting-edges may i be used when the first *group of -cutting edges has "become dulled. I

should-also=he noted-=that'-*we *have provided novel'and improved means ror preventing the cut-- ter elements from eng-aging a'nd throwing' foreign objects. "This -sub'stant-ial1y' reduces "the --'danger of injury to "the *"operator of the dev-ice and "to bystanders. flmy foreign objects-engagedby the knife element 12 will be'to'ssedegainst*the depending chains 68 and will thereafter be deflecte'd downwardly to fall -harrnles'sly "to the ground. At thesame -time, theseehainsWBtfperm-it' 't he fgrass *arid --*weelds to "extend upwardly therebetWeen-so as to remain ina "relativelyupright *position at alrtimes prior to the cutting opera-tron. ---'ihe flexible and =separable ""nature "of the pluraliw of chains eflectively prevents any mat'ting-cf i the weeds and gra'ss and-consequent raising-bi the assemblieswhicmmight" result from the use are rigid integral'guardsuchasa -plate.

F Its h0uId'=a1so' be" noted that We have completely eliminated any requirement "for -"castore'd wheels to support the cutter units. Gastm'ed wheel's, whih ha ve been' commonly usedpreviouslyin an attemp't'itoflseep skidding at 'a'minimumare' unsatisfactory 'beeauSe-the Wear excessively'when used at high 'rspe'eds, thereby necessitating frequent *replacements and increasing "costs of "operations substantially. "*With-'a sweep-back *o'r sweep forwardarrangement (if-putter I units, east'o're'd wheels are not -required arrd, in -"fa'ct, are not as satisfactory. Areastore'd "wheel, when driven at relatively high speed will "-sh immw vielentiy and will' set'up extreme vibrations Within II the entire machine. Such vibrations, of course, are highly undesirable for they increase the wear on the machine parts and prevent it from operating in a satisfactory manner.

Wherever hereinafter the expression meets the vertical plane or a similar expression is used with respect to the cutter element orbits and the axis of the ground engaging wheels, it is intended to include structure which conforms substantially with such specification.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of our invention.

What we hereby claim is:

1. In a rotary mower having an ambulant frame and at least one rotary cutter unit assembly pivoted adjacent one of its end portions to said frame for upward swinging movement of its opposite end portion, an elevating mechanism for such cutter unit assembly including an extensible and retractable hydraulic cylinder unit pivotally mounted on the frame of the mower and adapted to be connected to a source of hydraulic power and to be controllably extended and retracted when so connected, a substantially horizontal pivot member connected to one end portion of said cylinder unit and movable therewith, mechanism pivotally mounted on said mower frame extending to said pivot member and pivotally supporting the same upon such frame for vertical swinging movement and causing the same to move upwardly as said hydraulic cylinder is retracted, a lever arm pivotally mounted on said pivot member for pivotal movement thereabout and extending laterally of the mower frame, said lever arm being adapted to be pivotally connected to such rotary cutter unit assembly intermediate its end portions, and flexible means extending between said lever arm and said mower frame and limiting the extent of such pivotal movement of said lever arm about said pivot member and causing said lever arm to move upwardly throughout its length with said pivot member when said hydraulic cylinder is retracted and thereby causing said lever arm when so connected to such rotary cutter unit assembly to move the same upwardly therewith to an elevated and out of way position with respect to the rest of mower.

frame and at least one rotary cutter unit assembly pivoted adjacent one of its end portions to said frame, an elevating mechanism for such cutter unit assembly including an extensible and retractable hydraulic cylinder unit pivotally mounted on the frame of the mower and adapted to be connected to a source of hydraulic power and to be controllably extended and retracted when so connected, a substantially horizontal pivot member connected to one end portion of said cylinder unit for movement therewith, a pivot arm pivotally mounted on said mower frame and pivotally supporting said pivot member on the frame of the mower for swinging movement to cause the same to move upwardly as said hydraulic cylinder is retracted, a lever arm pivotally mounted on said pivot member for pivotal movement thereabout, said lever arm being adapted to be pivotally connected to such rotary cutter unit assembly intermediate the end portions of such assembly, and flexible anchor means connecting said lever arm to the frame of the mower and limiting the extent of pivotal movement of said lever arm and causin the same to pivot on said pivot member from a position approximating horizontal to a position approaching vertical when said hydraulic cylinder is retracted and said pivot member is raised to thereby cause such a rotary cutter unit as sembly when so connected to said lever arm to be moved upwardly to an elevated and out-ofway position with respect to the rest of the mower.

3. In a rotary mower having an ambulant frame and at least one rotary cutter unit assembly pivoted adjacent one of its end portions to said frame for upward swinging movement of its opposite end portion, an elevating mechanism for such cutter unit assembly including an extensible and retractable hydraulic cylinder unit pivotally mounted on the frame of the mower and adapted to be connected to a source of hydraulic power and to be controllably extended and retracted when so connected, a substantially horizontal pivot member connected to one end portion of said cylinder unit for movement therewith, a pivot arm pivotally connected to the mower frame mounting said pivot member upon the frame of the mower for swinging movement of the same in a vertical plane, said cylinder being positioned with respect to said arm to cause said pivot member to move upwardly when said cylinder is retracted and to move downwardly when said cylinder is extended, a lever arm pivotally mounted by one of its end portions on said pivot member for pivotal movement thereabout, said lever arm having its opposite end portion adapted for pivotal connection with such rotary cutter unit assembly intermediate the end portions of the latter and having a curved surface rigidly connected with said mounted end portion, and flexible anchor means connecting to said lever arm adjacent said pivot member to the frame of the mower and extending around said curved surface to cause said lever arm to pivot on said pivot member and move said opposite end portion in an upward direction when said hydraulic cylinder is retracted to thereby cause such a rotary cutter unit assembly when so connected to said lever arm to be moved upwardly to an elevated and out-of-way position.

4. In a rotary mower having an ambulant frame and at least one rotary cutter unit assembly pivoted adjacent one of its end portions for 2. In a rotary mower having an ambulant upward swinging movement of its opposite end portion, an elevating mechanism for such cutter unit assembly including a hydraulic cylinder unit pivotally mounted on the frame of the mower and adapted to be connected with a source of hydraulic power and to be controllably extended to one extreme position and retracted to its other extreme position when so connected, a substantially horizontal pivot member connected to one end portion of said cylinder unit for movement therewith, means for additional mounting of said pivot member for swinging movement of the same in a vertical plane, said cylinder being positioned with respect to said means to cause said pivot member to swing upwardly when said cylinder is moved toward one extreme position and to swing downwardly when said cylinder is moved to'its other extreme position, a lever arm mounted by one of its end portions on said pivot member for pivotal movement thereabout, said lever arm having its opposite end portion adapted for pivotal connection with such a rotary cutter unit assembly intermediate the end of the latter and having a curved surface rigidly connected with said mountfig-6456: 626

ed ii'dfliortion, am cable nrean emiectaao said curved surface-and cllow-ing the ou erad ctour s *theredf, "one end 'po'rtion -'of said cable means being-anchored at a posiacnaecausesard leverar riiber a'nd move said o'p" wa'ddirecti'o'n when=sa1d p'i-vot member 'ismove pwa'r'dly to thereby "s'e such arotary-cutter unitassembly whence connected to saiid leverarmto 'be moved upwardly to an lvatedarid out of way'-"'position.

5.""In a rotary mower "having an "ambulant frame and ac-least one rotary c'ut'ter unit assembly mounted to permit verticalmovement of the same and supported in part at.least bywhe'el structure,=mechanism'for maintaining suchwl'iel structure in contactwiththe ground at a lltimes despite t'r'aviel "over roughtrrain, said (mechanism including an "artiste-per" ed iby the frame, a "pivot shaft carrie'dby saidsrm, a lever arm mounted by one of its end portions on said shaft for swinging movement and having its opposite end portion adapted to be rigidly connected with such an assembly, said mounted end portion having a curved surface associated therewith and at least partially surrounding said shaft, a contractile type spring member having one of its ends relatively anchored, and cable structure connecting the free end of said spring with said curved surface and extending at least partially around said surface in a direction to urge said lever arm to swing its opposite end portion downwardly when said spring is tensioned to exert a constant downward pressure on the assembly, said cable structure being of a length to cause said spring to be tensioned when said wheel structure contacts the ground.

6. In a rotary mower having an ambulant frame and at least one vertically movable rotary cutter unit assembly supported in part at least by wheel structure, mechanism for maintaining such Wheel structure in contact with the ground at all times despite travel over rough terrain, said mechanism including an arm supported by the frame, a lever arm pivotally mounted on said arm on a substantially horizontal axis by one of its end portions and having its opposite end portion adapted to be rigidly but pivotally connected with such assembly, said mounted end portion of said lever arm having a curved rigid surface connected thereto and extending at least partially around the pivot axis of said lever arm, cable means connected to said curved surface and extending therearound in the direction said lever arm will pivot when such assembly moves downwardly, and resilient means connected to said cable means for urging said lever'arm to pivot in the same direction and thus exert a downward pressure upon such assembly.

'7. In a rotary mower having an ambulant frame and a pair of vertically movable rotary cutter unit assemblies supported in part at least by wheel structure, mechanism for maintaining such wheel structure in contact with the ground at all times despite travel over rough terrain, said mechanism including a pair of spaced arms supported by the frame, a lever arm pivotally mounted by one of its end portions on each of said arms and having its opposite end portion adapted to be rigidly connected with one of such assemblies, each of said mounted end portions of said lever arms having a curved surface connected thereto and extending at least partially around the pivot axis of the respective lever arm, and a contractile type spring member interps'eu wrii-1e "firmer tiision setween ears lever arms an -l'iavi'n' asrespecuveerrcscreens connected to said ui vedsiirfaces ai't 'poirits such as to "urge said-"'leve arm 1: to swing its-'opp'osite end portion downwa'rc'l nd the'reby exert'a *down wars ressurec on its-respective assembly.

8. 111 "a; rotary mower -"having an ambulant fra'me and a pair (if rotary cutter diiiit asse blies each extending laterally therefrom ingpivoted djacentoneo'f 5 its en'd 'portions for upward swi gi'ng movement of its --'oppesire e'nd p' rtionfand b'ei'n g s'u'ppdrted {at least partially by 'l'ieel structur eclianism for elevating such assernraires and -fo'rf maintainin'g such wlieel "striferare in contact' with the ground at-s11 times-during mowing opera-tions despite trav'elover rough terrain, s'aid mechanism including a hydraulic cylinder asseinloly 'a'dapt-ed to ibeconnectedwith a source' of-h' 'draulic-powe'r andto-becontrollably extended "and retracted when -so connected, -'-a pair of substantially horizontal pivot members connected to the opposite ends of said hydraulic cylinder assembly, a pair of spaced pivot arms supported by the frame adjacent the ends of said cylinder assembly and pivotally mounted for swinging movement in a vertical plane and each carrying one of said pivot members, a pair of lever arms each mounted by one of its end portions on one of said pivot members for swinging vertical movement of its opposite end portion, said opposite end portions being each adapted for rigid but pivotal connection with its respective cutter unit assembly to cause the assembly to be elevated when said pivot arm is raised by the retraction of said hydraulic cylinder, said mounted end portions of said lever arms each having a drum-like structure associated therewith and fixedly connected thereto, a contractile type spring interposed between said drum-like structures, a pair of cables one each connected to each end of said spring and extending around said drum-like structure from below and being connected thereto, said cables each being of such length to impose a tension upon said spring when said hydraulic cylinder unit is extended to cause said cables to urge the opposite end portions of assembly arms to swing downwardly and thereby maintain such wheel structure at all times during mowing operations in contact with the ground.

9. In a rotary mower having an ambulant frame and a rotary cutter unit assembly extending laterally therefrom and being pivoted adjacent one of its end portions for upward swinging movement of its opposite end portion and being supported at least partially by wheel structure, mechanism for elevating such assembly and for mantaining such wheel structure in contact with the ground at all times during mowing operations despite travel over rough terrain, said mechanism including a transversely extending hydraulic cylinder assembly mounted on such frame and adapted to be connected with a source of hydraulic power and to be controllably extended and retracted from one extreme position to its other extreme position when so connected, an arm pivotally mounted by its lower end portion on such frame for swinging movement on a substantially horizontal axis, a pivot shaft carried by the upper end portion of said arm and extending longitudinally of such frame and being connected to one end of said hydraulic cylinder assembly, the other end of said cylinder assembly being relatively fixed, a lever arm pivotallymounted by one of its end portions on said pivot 15 shaft and having its other end portion adapted to be rigidly but pivotally connected to such cutter unit assembly, the relatively fixed end of. said cylinder assembly being disposed to cause said arm to extend outwardly from vertical position when said cylinder assembly is extended to its extreme position, said mounted end portion of said lever arm having a curved surface associated therewith and connected thereto and extending at least partially around said pivot shaft, cable means connected to said curved surface and extending therearound in the direction said lever arm will pivot when such assembly moves downwardly, resilient means connected to said cable means for urging said lever arm to pivot in said direction and thus exert a downward pressure upon such assembly, said resilient means being disposed to exert such pressure only while said arm extends outwardly beyond vertical position, and additional cable means connected to said 16 curved surface and extending therearound in the opposite direction from said first mentioned cable means and being anchored outwardly of the pivoted axis of the lower end portion of said first mentioned arm whereby as said cylinder assembly contracts and said arm approaches vertical position, said lever arm will be caused to pivot on said pivot shaft and the opposite end portion will be caused to raise relative rapidly and to thereby elevate said cutter unit assembly.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,397,365 Cook Nov. 15, 1921 2,259,553 Clapper Oct. 21, 1941 2,325,870 Mott Aug. 3, 1943 2,485,383 Hoyt Oct. 18, 1949 2,624,999 Goodnight Jan. 13, 1953 

